Governor controlled friction clutch



y 4 B. STECHBART 2,318,433

GOVERNOR CONTROLLED FRICTION CLUTCH I Original Filed Sept. 16, 1940 4Sheets-Sheet 1 EOE- INVENTEIR EIRLJN/U ETEEHEART AT Y.

" y 1943. B. ST'ECHBART 2,318,433

common CONTROLLED FRICTION cw'rcn Original Filed Sept. 16, 1940 4Shets-Sheet 2 INVENTUR BRUNEI STEEHBART ATTY;

y 4, 1943- B.'SITECHBART 2,318,433

GOVERNOR CONTROLLED FRICTION CLUTCH v Original Filedsept. 16, 1940 4Sheets-Sheet ELI- 'INVENTUR BRUNEI EITEEHBART ATTY.

y B. STECHBART 2,318,433

GQVERNQR CONTROLLED FRICTION CLUTCH Original Filed Sept. 16, 1940 4Sheets-She'et 4 INVENTUR EIRLJNE] EITEEHBART ATTY v Patented May 4, 1943GOVERNOR CONTROLLED FRICTION CLUTCH Bruno Stechbart, Park Ridge, 111.,assignor to The Bell & Howell Company, Chicago, 111., a corporation ofIllinois GriginaI application September 16, 1940, Serial No. 356,963.Divided and this application September 13, 1941, Serial No. 410,743

8 Claims.

My invention relates particularly to a governor controlled yieldingfriction clutch which is particularly adapted for the control of anautomatic fire shutter of a motion picture projecting machine for thepurpose of obstructing the projection light at a low velocity or stoppedcondition of the projector mechanism to the end that the film at theprojection aperture of the machine is not damaged by the heat from theprojection light, this application being a division of my copendingapplication for United States Letters Patent, Serial No. 356,963, filedSeptemberlG, 1940, for improvement in Automatic fire shutter mechanism.

The general object of my invention resides in the provision of areliable and effective governor controlled friction clutch which isparticularly adapted for the control of a fire shutter and the frictionof which does not undesirably increase as the velocity of the drivingmember thereof increases. 7

With this object in view, my invention consists in certain features ofnovelty in the construction, combination and arrangement of parts bywhich the said object and certain other objects, hereinafter appearing,are effected, all as fully described with reference to the accompany ingdrawings, and more particularly pointed out in the appended claims.

In the said drawings Figure 1 is a partial View in front elevation of amotion picture projecting machine embodyingmy invention, with partsremoved and shown in section;

Figure 2 is a partial sectional view of the same, substantially on theline 22 of Figure 1;

Figure 3 is an enlarged sectional View of the governor controlledyielding friction clutch of my invention, substantially on the line 33of Figure Figure 4 is a view similar to Figure 3, showing parts indifferent positions than those in which they are shown in Figure 3;

Figure 5 is a sectional View substantially on the line 5-5 of Figure 3;

Figure 6 is an enlarged perspective view of one of the friction clutchmembers involved in Figures 3, 4 and 5;

Figure 7 is an enlarged perspective view of one of the governor weightmembers involved in Figures 3, 4 and 5;

Figure 8 is a partial view in front elevation of a motion pictureprojecting machine embodying another form of my invention, with partsremoved and shown in section;

one of the friction clutch members involved in.

Figures 10, 11 and 12; and

Figure 14 is an enlarged perspective view of one of the governor weightmembers involved in Fig,- ures 10, 11 and 12. g 7

Referring to the Figures 1 to 7, inclusive, of the drawings, ldesignates the frame of a motion picture projecting machine, and aforwardly extending mechanism shaft 2 is rotatably. mounted on thisframe by means of bearings, of which one is shown at 3. The shaft 2drives the projection mechanism of the machine, including a lightshutter 4 and an intermittent film feed cam 5 secured on this shaft, anda clutch drive member in the form of a rearwardly facing drum 6 is alsosecured on the shaft 2 and provides an external friction drive surface1.

A rearwardly extending motor or drive shaft 8, in parallelism with theshaft 2, is rotatably mounted on the frame I by means of bearings, ofwhich one is shown at 9, and a drive member I l is secured on theforward end of this shaft and provides an external friction drivesurface l2.

A link I3 is pivotally mounted on the frame I in parallelism with theshafts 2 and 8, as designated at It, and a lever I5 is intermediatelypivoted, as designated at l6, on the link I3 in parallelismwith thepivotal axis of the link. See particularly Figure 1. member I7,providing an external drive surface I8, is rotatably mounted, asdesignated at I9, on the lever l5 on an axis parallel to the pivotalaxis of the link I3 and spaced from the pivotal connection of the leverwith the link. The drive member i1 is thus mounted for universalmovement with the lever l5 in the plane of revolution the lever [5 beingguided in its movement by guides 2| and 22. A spring 23 is operative onan end of the lever I 5 to yieldably urge the drive member I! intoengagement with the drive membersfiand ll. 7 v V A manually actuatedcontrol member 24 is An intermediate drive pivotally mounted on theframe I, as designated at 25, and is yieldably maintained at oppositeends of its movement by an over center spring detent device, generallydesignated at 25. An eccentrically disposed stud 21 on the member 24 isengageable with the end of the lever I opposite thatengaged by thespring 23 to tilt the lever I5 in opposition to this spring when themember 24 is moved to one end of its movement for disengaging the drivemember H from the drive members 8 and II to stop operation of theprojector mechanism. The link I3 is provided with a stop arm 28engageable with the frame I to take the reaction of clutch releasingmovement of the lever I5. Movement of the control member 24 to theotherendof its .movement permits engagement of the drive member I! withthe drive members 6 and II by means of the spring 23. The clutchdisengaged positions of the drive member I! and relatedparts are shownin full lines, and the clutch engaged positions thereoflare shown inbroken lines in Figure 1.

Thus, is provided a simple and effective releasable friction clutchdrive for the projector mechas is usual with fire shutters, and theshutter is reciprocable, with pivotal movement of the arm 29, into andout of operative or light obstructing position; The operative positionof the shutter is shown in full lines and the inoperative positionthereof is shown in broken lines in Figure 1'.

A short shaft 33 is rotatable on the frame I, as designated at 34 inFigure 1, in coaxial relation with the shaft 2, and a driven clutchmemmer in the form .of a forwardly facing drum 35' is secured on thisshaft for rotation therewith and extends into the drum .member 5. SeeFigures 3, 4 and 5. A pair of right and left clutch arms36 are disposedwithin the drums ,6 and 35 and are intermediately pivotally mounted, asdesignated at 3?, on and eccentrically of the axis of the drumsrespectively on spaced axes disposed on one side of an axial plane ofthe drums. Corresponding portions of'these arms extend from theirpivotal axes toward the aforesaid axial plane and are provided at theirouter ends with friction rollers 38 frictionallyengageable with aradially internally facing friction clutch surface 39 of the drum 35 atdiametrically opposite points, corresponding with the aforesaid axialplane, to provide a friction clutch drive from the drum 6 to the drum35, these rollers being disengageable from the drum 35. See Figures 3,4, 5 and 6.

The other portions of the arms 36 extend toward each other and areprovided with counterbalance weights GI opposing centrifugal actuationof the arms, and a tension spring 42 is connected with the arms 36 andyieldably urges the arms to engage the friction rollers 38 with thesurface 39 of the drum 35 to form a yielding friction drive between thedrums 6 and 35.

A pair of right and left centrifugally actuated weight members 43 aredisposed within the drum 6 and 35 and are pivotally mounted, as

designated at 44, on and eccentrically of the axis of the drum 6respectively on spaced axes coaxial respectively with the pivotalmountings 31 of the clutch arms 35 and accordingly disposed at said sideof the aforementioned axial plane of the drums 6 and 35. These weightmembers extend from their pivotal axes on opposite sides respectively ofthe axis of the drums 6 and 35 and across the aforementioned axial planeto the other side thereof. Springs 45 See The weight members 43 areprovided with edge recesses '46 forclearance of the friction rollers 38and are provided with edge recesses 41 for clearance of the shaft 2 anda securing nut 49 thereon, the latter recesses being engageable with thenut 48 to provide stop means limiting centrifugal actuation .of theweight members, as shown in Figure 4. The weight members 43 are alsoprovided with abutment surfaces 49 engageable with their counterbalanceweights 4I of th clutch arms 35 to provide one way connections betweenthe clutch arms and the Weight members operative to effect disengagementof the clutcharms from the drum 35 with positioning of these weightmembers by the springs 45.

At a low velocity or stopped condition of the driving clutch drumS, theweight members 43 are retracted by the springs 45, see Figures 3 and 5,and the abutment surfaces 49,. engaging the counterbalance weights ofthe clutch arms .35, position the clutch arms in clutch releasedposition out of engagement with the driven clutch drum 35, the spring'42 being overcome in this condition. As the velocity of the drivingclutch drum 6 increases, see Figure 4, the weight member 43 arecentrifugally actuated .in opposition to the springs 45 and the abutmentsurfaces 49 are disengaged from the counterbalance weights M with theresult that the spring 42 actuates the clutch arms 36 intoclutch-engaged positions for the driving of the driven clutch drum '35.Ac cordingly, the pressure between the friction clutch members cannotbecome excessive with resulting excessive clutch driving friction as thevelocity of the driving drum 6 increases, the counterbalancing weights4| also tending toward this end.

A link 5| is pivotally connected at spaced points thereon with andeccentrically of the driven clutch drum 35, as designated at 52, andwith an end portion of the shutter arm 29 by means of a stud 53 on theshutter arm and slidably and pivotally engaging a longitudinallyextending slot 54 on this link. See Figures 1 and 2. As so connectedwith the shutter arm, the driven clutch drum 35 is operative on theshutter arm to actuate the shutter arm from operative position, as shownin full lines in Figure 1, to inoperative position, as shown in brokenlines in Figure 1, with movement of the drum 35 to either end of anangular movement thereof from an intermediate position of said angularmovement, thus providing for control in both directions of drive of theprojector mechanism, as is indicated in Figure 1. The slot 54, engagedwith the stud 53, provides a 1051'; motion connection permitting thedrum 35 to gather momentum with a view toward preventing stalling ofthis drum. 1

Movement of the shutter arm 29, which is yield- 7 ably urged intooperative position, and of the shutter arm is provided with anadjustable partially balancing counterweight device, generallydesignated at 56.

An arm 51 is pivotally mounted on the frame I, as designated at 58, andis engageable, as designated at 59, with the shutter arm 29 to actuatethe shutter arm into operative position. A spring 6| actuates the arm 51in the direction to actuate the shutter arm into operative position. Aneccentrically disposed stud 62 on the clutch control member 24 isengageable with the arm to actuate the same out of engagement with theshutter arm 29 when the clutch control member is in clutch-engagedposition, as shown in broken lines in Figure 1. When the clutch controlmember is in clutch-disengaged position, the stud 62 is disengaged fromthe arm 5'1, thus permitting the spring 6| to act on the shutter arm 29through the arm 57 to facilitate movement of the shutter arm intooperative position when the driving clutch is disengaged, as shown infull lines in Figure 1.

Referring to Figures 8 to 14, inclusive, of the drawings, 83 designatesthe frame of a motion picture projecting machine, and a forwardlyextending motor and projection mechanism drive shaft 6 is rotatablymounted on this frame by means of bearings. one of which is shown at 65.See Figures 1 and 2. A sleeve 65 is secured with the frame 63 inconcentric relation with and surrounding a portion of the shaft 64, andanother sleeve 6'! is rotatably mounted on the exterior of the sleeve 66in concentric relation with the shaft 64 by means of a roller bearing68. A ring 69 of friction material such as cork is secured on theexterior of the rotatable sleeve 61 and provides a radially externallyfacing friction clutch surface H.

A clutch drive disk member 12 is secured on the shaft 64 for rotationtherewith. A pair of clutch arms 13, external of the clutch surface H,are intermediately pivotally mounted, asdesignated at 14, on andeccentrically of the axis of the disk and respectively on axes disposedin diametrically opposite relation with respect to the axis of the disk.See Figures 10, 11, 12 and 13. Corresponding portions of these armsextend from their pivotal axes and are formed to provide frictionsurfaces engageable with the clutch surface H at diametrically oppositepoints to provide a friction clutch drive from the disk member 12 to thedriven clutch member or sleeve 67, these arms being disengageable fromthe clutch surface H. The other portions of the arms 13 extend fromtheir pivotal axes in generally opposite relation with the portions 15thereof, as designated at 16, and provide counterbalance weightsopposing centrifugal actuation of the arms.

A pair of centrifugally actuated Weight members H, external of theclutch surface H, are pivotally mounted, as designated at E8, on andeccentrically of the axis of the disk 12 and respectively on axesdisposed in diametrically opposite relation with respect to the axis ofthe disk and coaxial respectively with the pivotal mountings of theclutch arms 73. See Figures 10, 11, 12 and 14. Pivotal movement of theweight members TI is limited by lateral lugs 19 on the weight membersand extending into bores 85 of the disk 12.

U-shaped springs 82 embrace studs 83 of the pivotal mountings of theclutch arms 13 and weight members 11, and corresponding, ends. thereofare engaged with the disk 12, as designated at 84. The other ends ofthese springs engage,

respectively, the lugs 19 of the weightmembers I1 and yieldably urge theweight members in opposition to centrifugal actuation thereof.

The weight members 11 are provided with abutment lugs engageablerespectively with the counterbalance portions 16 of the correspondinglypivoted clutch arms 13 to provide one-way connections between the weightmembers and the clutch arms operative to effect disengagement of theclutch arms from the driven clutch member with positioning of the weightmembers by the springs 82.

Springs 86 have their intermediate portions coiled respectively aboutthe studs 83, and corresponding ends of these springs are engagedrespectively with the corresponding clutch arms 13, and the other endsof these springs are engaged respectively in grooves '98 of the lugs 85of corresponding weight members 11 to yieldably urge the clutch membersinto clutch-engaged position.

At a low velocity or stopped condition of the clutch drive disk 72, theweight members 11 are retracted by the springs 82, see Figure 10, andthe abutment lugs 85, engaging the clutch arms, position the clutch armsin clutch-released position out of engagement with the clutch surface1|, the springs 88 being overcome in this condition. As the velocity ofthe clutch drive disk increases, see Figure 11, the weight members 11are centrifugally actuated in opposition to the springs 82, and the lugs85 are disengaged from the clutch arms, with the result that the springs86 actuate the clutch arms into clutch-engaged positions. Accordingly,the pressure between the friction clutch members cannot become excessivewith resulting excessive clutch driving friction as the velocity of theclutch drive member increases, the counterbalancing of the clutch armsalso tending toward this end.

A shutter arm 81 is pivoted, as designated at 88, on the frame 63 on arearwardly extending axis, and one end of this arm is provided with afire shutter 89 which is reciprocable, with pivotal movement of the arm81, into and out of opertaive or light obstructing position. The shutterarm is yielda'bly urged into operative position.

A counterbalanced arm 9! is secured on the clutch-driven sleeve 67, anda link 92 is pivotally connected at spaced points thereon with the arm9| and eccentrically of the driven clutch member, as designated at 93,and with an arm portion 94 of the shutter arm 81 by means of a .stud 95on this arm portion and slidably and clusive.

While I have thus described my invention, I do not wish to be limited tothe precise details described, as changes may be readily made withoutdeparting from the spirit of my invention,

but having thus described my invention, I claim as new and desire tosecure by Letters Patent the following:

1. In a governor controlled friction clutch, the combination withrotatable coaxial driving and driven members of which the driven memberforms a friction clutch member and is provided with a radially facingfriction clutch surface, of a second friction clutch member driven withsaid driving member and pivotally mounted 'eccehtrically of the 'axisthereof for engaging and disengaging said clutch surface, spring meansyieldably urging said second clutch member into engagement with saidclutch surface, a centr'ifugally actuated weight member driven with saiddriving member and pivotally mounted eccentricall'y thereof, a secondspring means yieldably urging said weight member in opposition tocentrifugal actuation thereof, and a one-way connection between saidsecond clutch and weight members operative to effect disengagement ofsaid second clutch member from said clutch surface with positioning ofsaid weight member by said second spring means.

2. In a governor controlled friction clutch, the combination withrotatable coaxial driving and driven members of which the driven memberforms a friction clutch member and is provided with a radially facingfriction clutch surface, of a second friction clutch member driven withsaid driving member and mounted for movement radially thereof forengagement with and disengagement from said clutch surface, acounterbalance operative on said second clutch member opposingcentrifugal actuation of said second clutch member, spring meansyieldably urging said second clutch member into engagement with saidclutch surface, a centrifugally actuated weight member driven with saiddriving member and mounted for movement radially thereof, a secondspring means yieldably urging said weight member in opposition tocentrifugal actuation thereof, and a one-way connection between saidsecond clutch and weight members operative to effect disengagement ofsaid clutch member from said clutch surface with positioning of saidweight member by said second spring means. I

3. In a governor controlled friction clutch, the combination withrotatable coaxial driving and driven members of which the driven memberforms a friction clutch member and is provided with a radially facingfriction clutch surface, of a second friction clutch member pivotallymounted on and eccentrically of the axis of said driving member forengagement with and disengagement from said clutch surface, spring meansyieldably urging said second clutch member into engagement with saidclutch surface, a centrifugally actuated weight member pivotally mountedon said driving member in coaxial relation with said clutch member, asecond spring means yieldably urging said weight member in opposition tocentrifugal actuation thereof, and a one- Way connection between saidsecond clutch and weight members operative angularly of the pivotalmovement thereof to effect disengagement of said second clutch memberfrom said clutch surface with positioning of said weight member by saidsecond spring means.

4. In a governor controlled friction clutch, the combination withrotatable coaxial driving and driven members of which the driven memberis provided with a radially facing friction clutch surface, of afriction clutch arm pivotally mounted intermediately thereof on andeccentrically of the axis of said driving member and provided at one endwith a friction clutch formation engageable with and disengageable fromsaid clutch surface and the other end of said arm being weighted toprovide a counterbalance opposing centrifugal actuation of said arm,spring means yieldably urging said arm into engagement with said clutchsurface, a centrifugally actuated weight member pivotally mounted onsaid driving member in coaxial relation with said arm, a second springmeans yieldably urging said weight member in opposition to centrifugalactuation thereof, and a one-way connection between said other end ofsaid arm and said weight member to effect disengagement of said arm fromsaid clutch surface with positioning of said weight member by saidsecond spring means.

5. In a governor controlled friction clutch, the combination withrotatable coaxial driving and driven members of which the driven memberforms a friction clutch member and is provided with a radiallyinternally facing friction clutch surface, of a second friction clutchmember within the enclosure of said clutch surface and pivotally mountedon and eccentrically of the axis of said driving member for engagementwith and disengagement from said clutch surface, spring means yieldablyurging said clutch member into engagement with said clutch surface, acentrifugally actuated weight member within the enclosure of said clutchsurface and pivotally mounted on and eccentrically of the axis of saiddriving member, a second spring means yieldably urging said weightmember in opposition to centrifugal actuation thereof, stop meanslimiting centrifugal actuation of said weight member, and a one-wayconnection between said second clutch and weight members operative toeffect disengagement of said second clutch member from said clutchsurface with positioning of said weight member by said second springmeans.

6. In a, governor controlled friction clutch, the combination withrotatable coaxial driving and driven members of which the driven memberis provided with a radially internally facing friction clutch surface,of a pair of friction clutch arms within the enclosure of said clutchsurface and pivotally mounted on and eccentrically of the axis of saiddriving member respectively on spaced axes disposed on one side of anaxial plane of said driving member and extending from their pivotal axestoward, said axial plane for engagement with said clutch surface atdiametrically opposite points corresponding with said plane, springmeans yieldably urging said clutch members into engagement with saidclutch surface, of a pair of centrifugally actuated weight memberswithin the enclosure of said clutch surface and pivotally mounted on andeccentrically of the axis of said driving member respectively on spacedaxes disposed on said side of said axial plane and extending from theirpivotal axes on opposite sides respectively of the axis of said drivingmember and across said axial plane to the other side thereof, a secondspring means yieldably urging said weight members in opposition tocentrifugal actuation of said weight members, stop means limitingcentrifugal actuation of said weight members, and one-way connectionsbetween said clutch arms and weight members operative to effectdisengagement of said clutch arms from said clutch surface withpositioning of said weight members by said second spring means.

7. In a governor controlled friction clutch, the combination withrotatable coaxial driving and driven members of which the driven memberforms a friction clutch member and is provided with a radiallyexternally facing friction clutch surface, of a second friction clutchmember external of said surface and pivotally mounted on andeccentrically of the axis of said driving member for engagement with anddisengagement from said clutch surface, spring means yieldably urgingsaid second clutch member into engagement with said clutch surface, acentrifugally actuated weight member external of said clutch surface andpivotally mounted on and eccentrically of the axis of said drivingmember, a second spring means yieldably urging said weight member inopposition to centrifugal actuation thereof, and a one-Way connectionbetween said second clutch and weight members operative to effectdisengagement of said second clutch member from said clutch surface withpositioning of said weight member by said second spring means.

8. In a governor controlled friction clutch, the combination withrotatable coaxial driving and driven members of which the driven memberis provided with a radially externally facing friction clutch surface,of a pair of friction clutch arms external of said surface and pivotallymounted on and eccentrically of the axis of said driving memberrespectively on axes disposed in diametrically opposite relation withrespect to the axis of said driving member and extending from theirpivotal axes for engagement with said clutch surface at diametricallyopposite points, a pair of centrifugally actuated weight membersexternal of said surface and pivotally mounted on and eccentrically ofthe axis of said driving member respectively on axes disposed indiametrically opposite relation with respect to the axis of said drivingmember and respectively corresponding with the clutch arm axes, a pairof springs respectively operative between correspondingly pivoted clutcharms and weight members for yielclably urging said clutch arms intoengagement, with said clutch surface, a second pair of springsrespectively operative on said weight members and yieldably urging saidweight members in opposition to centrifugal actuation of said weightmembers, stop means limiting centrifugal actuation of said weightmembers, and one-way connections respectively between correspondinglypivoted clutch arms and weight members operative to eifect disengagementof said clutch arms from said clutch surface with positioning of saidweight members by said second pair of springs.

BRUNO STECHBART.

